Field
The present disclosure relates to functionalized graphene compositions and their application as gas-barrier and/or moisture-barrier elements.
Description of Related Art
In the area of packaging, barrier films provide a lower-cost method as compared to cans and other packaging. In wide use is nontransparent metal-based films that consist of metalized polymers or a based on aluminum foil. However, such films typically do not enable customers to view the product to verify quality before purchase. In addition, metal-based packaging may not be microwaveable, limiting the manufacturer's ability to sterilize the product by microwave sterilization. Additional considerations for plastic packaging are a desire to avoid the presence of chlorine for purposes of recycling and a desire to avoid using Bisphenol A (BPA) due to market demand and perceived health risk. As a result, current transparent barrier-films consist of Polyvinylidine Chloride (PVDC), PVC, Ethylene Vinyl Alcohol (EVOH), Polyvinyl Alcohol (PVA), low density polyethylene (LDPE), or films with ceramic coatings like Silicone Oxides (SiOx) or Aluminum Oxides (AlOx).
As products require longer shelf-lives, the need for in-packaging sterilization and for packaging to be efficient barriers of oxygen and water have become driving considerations. To help address oxygen permeation into the PET barrier films three main barrier technologies have been developed: co-injection, coatings, and oxygen scavengers. The resulting barriers tend to be complex with many layers.
Consequently, there is a need for a low-cost coating with strong barrier properties, high mechanical strength but that is flexible, metal-free and microwaveable.